Boiler-tube expander



(No Model.)

7 STRE R. 3 TUBE NDER. No. 519,278. Patented May 1, 1894.

W/TNESSES: INVENTOR A 7'TOHNEYS.

PATENT. OFFICE.

HENRY STREOKER, OF MARIETTA, OHIO.

BOILER-TUBE EXPANDER.

SPECIFICATION forming part of Letters Patent No. 519,278,dated May 1, 1894.

Application filed March 14., 1894. Serial No. 503,576. (No model.) i v To all whom it may concern.-

Be it known that I, HENRY STREOKER, of Marietta, in the county of Washington and State of Ohio, have invented a new and useful Improvement in Boiler-Tube Expanders, of which the following is a specification.

My invention relates to that form of tube expander which comprises a tapering central mandrel, a hub rotating on the same and carrying small steel rollers which bear against the inner periphery of the tube, and a stop collar arranged about the mandrel outside the hub and adapted to bear against the tube sheet and serve as a guide for the mandrel when rotated. 1

My invention consists in the special con; struction and arrangement of an embracing frame for each roller adapted to play in recesses or openings in the revolving rollers, in

such a way as to allow the rollers to bear on their outside faces against the inner periphery of the tube to be expanded, and on their inner sides directly against the mandrel, said boxes or frames being so constructed as to permit a maximum outward movement of the rollers without allowing the rollers to drop out when the hub is on the smaller end of the mandrel.

Figure 1 is a side view; Fig. 2 a longitudinal section and Fig. 3 a transverse section through the line 33 of Fig. 1.

In the drawings A represents the tapering mandreLB is the rotary hub having a hole through it large enough to receive the largest portion of the mandrel, and O is the stop collar whose lugs a a bear against the tube sheet of the boiler, and hold this collar'stationary while the mandrel turns inside of the same.

As so far described the parts do not dilfer materially from those of. the tube expanders already in use.

At three points: on the periphery of the hub B there are recesses or chambers cut through to the interior bore in which are contained rectangular boxes or frames D which are closed upon their four sides but are openat top and bottom. These boxes are of tapering form, their outerfaces being somewhat smaller than their inner faces, and their outer faces being smaller than the holes in the hub in which they play, while the inner faces are larger than these holes. These boxes are inserted into these holes from the interior bore ofthe hub, and are then projected outwardly through the holes, but by reason of their taper are not permitted to pass entirely through said holes, their inner faces being larger than the holes. This prevents these boxes from ever falling through the hub away from the mandrel. In each of these boxes is retained loosely a steel roller E whose diameter is somewhat less than the transverse dimension of the openings in the outer faces of the boxes, so that these rollers while retained loosely in the boxes, that they may rotate when projected to contact with the inner peripheryof the tube, they nevertheless cannot fall out of said boxes. As these boxes are open at top and bottom these rollers bear with their outer faces directly against the tube to be expanded, and with their innerfacesbeardirectly against the mandrel. This is an important feature, for when the mandrel is turned its frictional contact with the inner face of these rollers impart an individual rotation to the rollers about their own axes that causes them to roll around and against thetube in the same direction that the mandrel is rotated that gives a very practical and effective result. This same construction permits the largest possible opening in the hub so that a maximum range of expanding movement for the rollers outwardly through the hub is obtained, Without any liability of the rollers to fall inwardly and get out of position.

F is a washer and G a nut to prevent the hub and stop collar from slipping entirely off the mandrel when not in use, thus preventingtheseparation and loss of the rollers E which have nothing to hold them in place if the hub B comes off the mandrel.

Having thus described my invention, what I claim as new, and desire to secure by Letters Patent, is-

1. In a boiler tube expander, the combination with the tapering central mandrel, of a rotating hub turning upon the mandrel and having recesses in its periphery outwardly adjustable frames arranged in said recesses and open at top and bottom and containing rollers arranged in direct contact with the mandrel through said frames, and adapted to be projected through the said frames to contact with the tube to be expanded the said frames hav- ICQ ing openings on their inner faces larger than the diameter of the rollers and on their outer faces smaller than the diameter of the rollers substantially as shown and described.

2. In a boiler tube expander, the combina tion with the tapering central mandrel; ot' a rotating hub having outwardly adjustable frames made larger at their ,sides next the mandrel whereby they are locked or permanently retained within recesses in the hub and open at top and bottom, and freely moving rollers retained in said frames in direct contact with the mandrel substantially as and for the purpose described.

3. In a boiler tube expander, the combination with the central tapering mandrel; of a rotating hub with tapering openings in its periphery converging outwardly, and frames HENRY STREGKER.

Witnesses:

L. A. ZIEGLER, F. O. AUDIBERT. 

